首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   9762篇
  免费   306篇
各国政治   466篇
工人农民   326篇
世界政治   884篇
外交国际关系   436篇
法律   5359篇
中国政治   68篇
政治理论   2473篇
综合类   56篇
  2021年   62篇
  2020年   113篇
  2019年   158篇
  2018年   225篇
  2017年   221篇
  2016年   255篇
  2015年   156篇
  2014年   198篇
  2013年   1200篇
  2012年   253篇
  2011年   245篇
  2010年   234篇
  2009年   260篇
  2008年   279篇
  2007年   283篇
  2006年   264篇
  2005年   250篇
  2004年   267篇
  2003年   234篇
  2002年   214篇
  2001年   377篇
  2000年   365篇
  1999年   262篇
  1998年   175篇
  1997年   153篇
  1996年   95篇
  1995年   123篇
  1994年   109篇
  1993年   104篇
  1992年   190篇
  1991年   193篇
  1990年   184篇
  1989年   187篇
  1988年   175篇
  1987年   196篇
  1986年   161篇
  1985年   169篇
  1984年   158篇
  1983年   129篇
  1982年   111篇
  1981年   125篇
  1980年   71篇
  1979年   114篇
  1978年   78篇
  1977年   58篇
  1976年   50篇
  1975年   59篇
  1974年   70篇
  1973年   75篇
  1972年   55篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
A 1990 report prepared by the Office of Inspector General estimated that as much as $1 billion is lost to the Medicare program annually because (i) secondary payor situations are not detected and (ii) insurance companies often do not pay when they are required to be the primary payors. Office of Inspector General, No. A-09-98-00151, April 1990, Medicare and Medicaid Guide (CCH) [symbol: see text] 39,112, at 25,649. In order to better enforce the MSP provisions, suggestions have been made at the Congressional level to impose sanctions against providers who demonstrate a pattern of inappropriate billing practices such as double billing, repeated failures to screen beneficiaries for other insurance coverage, and the repeated submission to Medicare of bills that should be submitted to another payor. (See the Subcommittee Report on erroneous payments under the MSP program, supra.) Although authority for such sanctions has yet to be adopted, given the fiscal problems currently plaguing the federal government, providers can expect increased enforcement of the MSP provisions as a means of reducing Medicare costs, and should review their screening and billing practices accordingly.  相似文献   
105.
Recent theory views adolescent behavior as nested in an ongoing system of family relationships. In keeping with this focus, differences in family functioning of high vs. low identity achievement youth were examined and variables to account for differing identity levels were explored. However, the hypothesized relationship (Circumplex Model) between family type and communication was also examined. Subjects were 411 male students, 18–24 years of age, belonging to intact nuclear middle-class homes, who resided with parents in urban areas. Measures used were the Identity Achievement Scale, Family Adaptability and Cohesion Evaluation Scale, and the Parent-Adolescent Communication Scale. Results supported an association between balanced family type and effective communication (p.001). Significant differences in the family types were found (p.001), with high identity subjects belonging to balanced families, experiencing more openness (p.01) and less problems (p.01) in communicating with parents. Openness with father, mother, and problems with father emerged as significant discriminants. There are important implications for counselling and therapy with youth, placing family at the center of the psychosocial milieu influencing their development.Received Ph.D. from H.P. University. Research interests: adolescent psychosocial development, youth, identity, and family influences.Received M.A.; Ph.D. from Boston University; Panjab University. Research interests: family interiors, women studies, life stress, self image (DAP), sexuality, myths, holistic healing, and tribal women.  相似文献   
106.
This study concerns the relationship between knowledge of drug culture and substance use. Results from a sample of 2,635 middle and high school students indicate that (1) knowledge of drug culture is positively correlated with substance use; (2) drug knowledge is more reliable and coherent in older youth; (3) drug knowledge is unrelated to other kinds of knowledge acquired in school; (4) youth exposed to peers' substance use in school have more drug knowledge; and (5) the earlier young people begin using drugs and alcohol, the more they know about the drug culture. Results suggest that knowledge of the drug culture may be an unobtrusive indicator of substance use problems.This project was made possible by a grant from the Tulsa Psychiatric Center, Tulsa, Oklahoma.Received Ph.D. from University of California at Berkeley in personality psychology. Research interests include school dropouts, substance use, delinquency, identity, narcissism, and health. To whom correspondence should be addressed.Received Ph.D. from University of California at Berkeley in personality psychology. Research interests include school dropouts, substance use, delinquency, personal commitments, identity, narcissism, and health.Received Ph.D. from University of California at Berkeley in personality psychology. Research interests include moral development and personality.  相似文献   
107.
108.
109.
110.
Isoenzyme band patterns of animal blood erythrocyte acid phosphatase (EAP) and phosphoglucomutase-1 (PGM) were studied by isoelectric focusing on ultrathin polyacrylamide gels. For blood from all animals tested (dog, cat, cow, sheep, and goat), the overall band patterns for both isoenzymes were different from those of the most common human types of these enzymes, although some animal EAP and PGM bands appeared in the human band areas. When mixtures of human and animal red blood cells were studied, it was found that misinterpretation of human types was possible only if the overall band pattern of the mixtures was ignored. For the animal blood tested, the strong PGM bands appearing outside the human band areas could be used as "markers" for the possible presence of animal blood in the samples tested.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号